1. Field of the Invention
The present invention relates generally to a method for analyzing the surface and the near-surface layers of a solid and, more specifically, to a method that utilizes activating actions to analyze the physical and the chemical properties of the layers.
2. Description of the Related Art
Physical and chemical properties vary substantially between a surface or a near-surface layer of a solid and the bulk of its structure. In many respects, the properties comprised for the surface layer govern the behaviors of the solid in different media and in the fields of various forces. A basic understanding of these properties paves the way for scientifically based modifications of the surface layer for the purposes of scientific and medicinal progress. Information obtained from an analysis of the surface layer additionally provides a means for industries to control the surface quality of products with a greater precision. Examples of industries include those in the fields of protective coatings, microelectronics or nanoelectronics.
It is important that the surface layer of a solid is preserved for the purposes of analyzation. The present invention teaches a method to preserve and to analyze a surface layer. A search of the prior art revealed no references that teach the claims of the present invention; however, the steps taught in U.S. Pat. No. 5,683,179 to Lowry are related.
Lowry discloses a method to detect the conductive state in an energized superconductor. Lowry teaches the following consecutive steps: (1) cooling a superconducting device to a preselected operating temperature; (2) activating a thermoluminescent sensor by irradiating the sensor with periodic pulses at a preselected radiation; and, (3) energizing the superconducting device by means of heating the sample. Lowry utilizes well-known and classic methods of thermoluminescense to accomplish the protection of superconductive devices. The activation steps taught in the present method alternatively vary in order and in quantum to preserve the surface layer of a solid for the purpose of analyzing the properties.
A method for analyzing physical properties of the surface layer of a solid is known, involving the activation of the surface layer of a solid by low-temperature plasma (LTP) followed by deactivation of the surface layer during which a thermoluminescence spectrum is recorded. The LTP used in this method is ignited by an unmodulated voltage with a frequency of 40.68 MHz at a 10-Pa pressure of a plasma-generating gas, the duration of the sample activation by LTP being from 10 s to 9 min (see A. A. Kalachev, etc., “Plasma-induced Thermoluminescence—a New Method for Investigating Supramolecular Architectures and Temperature Transitions in Polymers and Other Solid Surfaces”, Applied Surface Science 70/71 (1993), pp. 295-298 (a copy is attached)).
This engineering solution is taken as a prototype of the variant of the method as per claim 3 of the present invention.
The disadvantage of the prototype method is a modifying influence of the LTP with said parameters upon the surface layer of the sample investigated, which results in insufficiently reliable information on physical and chemical properties of this layer. First of all, this is due to strict plasma parameters used in the prototype, namely, a high pressure of a plasma-generating gas (10 Pa) and relatively long (10 s and more) duration of plasma activation. Both factors lead to overheating of the surface layer and a decay of arising active states already in the course of plasma treatment. For example, as seen from FIG. 4 of the prototype, the luminescence intensity typically falls with increasing treatment time. Moreover, said strict plasma parameters lead to other physical-chemical changes in the surface layer being analyzed.
In addition, in the mode of isothermal luminescence (see FIG. 3, paper by A. A. Kalachev etc.) the curves obtained according to the known method and illustrating the dependence (decrease) of thermoluminescence on time from the moment the LTP activation of the sample is over have no characteristic features; therefore, during this period of time no useful information on the surface structure or surface physical-chemical processes was obtained using said method. The curves are only used as a means for the determination of the moment when heating aimed at deactivation of the surface layer of a solid has to be started.